Surface treatments for preventing hydrocarbon thermal degradation deposits on articles

Abstract

A method of preventing thermal hydrocarbon degradation deposits on a surface of a gas turbine component, the method includes providing the turbine component comprising the surface configured for contacting a hydrocarbon fluid, wherein the substrate comprises a material having a nominal liquid wettability sufficient to generate, with reference to an oil, a nominal contact angle, disposing a plurality of features on the substrate to form an anti-deposition surface texture, wherein the plurality of features have a size, shape, and orientation selected such that the surface has an effective wettability sufficient to generate, with reference to an oil, an effective contact angle of greater than the nominal contact angle, and the features comprise a width dimension (a), and a spacing dimension (b), wherein the features prevent the hydrocarbon fluid from penetrating into the surface texture and thereby reduce the adhesion of the thermal hydrocarbon deposits to the surface.

What is claimed is: 
     
       1. A method of preventing thermal hydrocarbon degradation deposits on a surface of a gas turbine component, the method comprising:
 providing a turbine component within a combustion chamber where the component is contacted by hydrocarbon fuel or combustion products thereof during operation of the chamber, 
 supplying hydrocarbon fluid to the combustion chamber and 
 combusting the hydrocarbon fluid within the chamber, 
 wherein the surface of the component comprises a material having a nominal liquid wettability sufficient to generate, with reference to an oil, a nominal contact angle; 
 wherein a plurality of features have been disposed on the surface of the component to form an anti-deposition textured surface, wherein the plurality of features have a size, shape, and orientation selected such that the surface has an effective wettability sufficient to generate, with reference to an oil, an effective contact angle of greater than the nominal contact angle; and 
 wherein the features comprise a width dimension (a), and a spacing dimension (b), and wherein the features prevent the hydrocarbon fluid or combustion product thereof from penetrating into the textured surface and thereby reduce adhesion of thermal hydrocarbon deposits to the textured surface of the turbine component. 
 
     
     
       2. The method of  claim 1 , wherein the plurality of features are configured to achieve a capillary pressure is greater than a Laplace pressure for a droplet of the hydrocarbon fluid. 
     
     
       3. The method of  claim 1 , wherein the plurality of features are configured to achieve a capillary pressure greater than the Bernoulli pressure of a droplet of the hydrocarbon fluid impacting the textured surface. 
     
     
       4. The method of  claim 1 , wherein at least a subset of the plurality of features protrude above the surface of the gas turbine component. 
     
     
       5. The method of  claim 4 , wherein at least a subset of the protruding features has a shape selected from the group consisting of a cube, a post, a rectangular prism, a cone, a cylinder, a pyramid, a trapezoidal prism, and a hemisphere or other spherical portion. 
     
     
       6. The method of  claim 5 , wherein the subset of the protruding features comprise a plurality of posts, and wherein the width dimension (a) is less than about 25 micrometers, a ratio of b/a is between about 0.1 and about 6, and a ratio of a height dimension (h) to the width dimension (a) is less than about 10. 
     
     
       7. The method of  claim 5 , wherein the subset of the protruding features comprise a plurality of posts, and wherein the width dimension (a) is less than about 5 micrometers, and a ratio of b/a is between about 0.5 and about 4. 
     
     
       8. The method of  claim 5 , wherein the subset of the protruding features comprise a plurality of posts, and wherein the width dimension (a) is less than about 1 micrometers, and a ratio of b/a is between about 0.5 and about 2. 
     
     
       9. The method of  claim 1 , wherein at least a subset of the plurality of features is a plurality of cavities disposed on the textured surface. 
     
     
       10. The method of  claim 9 , wherein the width dimension (a) is less than about 25 micrometers, a ratio of b/a is less than about 6, and a ratio of a height dimension h to the width dimension (a) is less than about 10. 
     
     
       11. The method of  claim 9 , wherein the width dimension (a) is less than about 5 micrometers, and a ratio of b/a is less than about 4. 
     
     
       12. The method of  claim 9 , wherein the width dimension (a) is less than about 1 micrometer, and a ratio of b/a is less than about 2. 
     
     
       13. The method of  claim 1 , wherein the features comprise at least one, material selected from the group consisting of a ceramic, an intermetallic compound, and a polymer; wherein the ceramic comprises a material selected from the group consisting of titanium nitride, titanium carbonitride, chromium nitride, boron nitride, silicon carbide, electroless nickel, and aluminum nitride and combinations thereof; wherein the intermetallic compound comprises nickel aluminide, and titanium aluminide, and combinations thereof; and wherein the polymer comprises polytetrafluoroethylene, fluoroacrylate, fluoroeurathane, fluorosilicone, fluorosilane, modified carbonate, silicones and combinations thereof. 
     
     
       14. The method of  claim 1 , wherein the hydrocarbon fluid is selected from the group consisting of crude oil, products distilled from crude oil, industrial lubricants, bearing oil, and light turbine oil. 
     
     
       15. A method of preventing coke deposits on a surface of a gas turbine component, the method comprising:
 providing a turbine component within a combustion chamber where the component is contacted by hydrocarbon fuel or combustion products thereof during operation of the chamber, wherein the surface of the component comprises a material having a nominal liquid wettability sufficient to generate, with reference to an oil, a nominal contact angle; 
 supplying hydrocarbon fluid to the combustion chamber and 
 combusting the hydrocarbon fluid within the chamber, 
 wherein a plurality of features have been disposed on the surface of the turbine component to form an anti-coking textured surface, wherein the plurality of features have a size, shape, and orientation selected such that the surface has an effective wettability sufficient to generate, with reference to an oil, an effective contact angle of greater than the nominal contact angle; and 
 wherein the features comprise a width dimension (a), and a spacing dimension (b), and wherein the features prevent the hydrocarbon fluid or combustion product thereof from penetrating into the textured surface and thereby reduce adhesion of coke deposits to the textured surface of the turbine component. 
 
     
     
       16. The method of  claim 15 , wherein at least a subset of the plurality of features protrude above the textured surface of the gas turbine component. 
     
     
       17. The method of  claim 16 , wherein the subset of the protruding features comprise a plurality of posts, wherein a ratio of b/a is in a range of about 0.5 to about 2, and a ratio of a height dimension h to the width dimension (a) is less than about 1. 
     
     
       18. The method of  claim 15 , wherein at least a subset of the plurality of features is a plurality of cavities disposed on the textured surface. 
     
     
       19. The method of  claim 18 , wherein the dimensions of the plurality of cavities comprise a ratio of b/a in a range of about 0.5 to about 2, and a ratio of a height dimension h to the width dimension (a) is less than about 1. 
     
     
       20. A combustor for a gas turbine engine, comprising:
 a combustion chamber configured to contain a hydrocarbon fluid injected into the combustor; and 
 a splashplate disposed at an end of the combustion chamber, the splashplate having a surface that is contacted with the hydrocarbon fluid or combustion product thereof, wherein the splashplate comprises a material having a nominal liquid wettability sufficient to generate, with reference to an oil, a nominal contact angle; 
 a plurality of features disposed on the splashplate surface to form a textured anti-coking surface, wherein the plurality of features have a size, shape, and orientation selected such that the textured anti-coking surface has an effective wettability sufficient to generate, with reference to an oil, an effective contact angle of greater than the nominal contact angle; and wherein 
 the features comprise a width dimension (a), and a spacing dimension (b), and wherein the features prevent hydrocarbon fluid or combustion product thereof from penetrating into the textured anti-coking surface and thereby reduce adhesion of a coke deposit to the textured anti-coking surface, 
 wherein a ratio of b/a is less than about 2, and a ratio of h/a is less than about 5.